Positions file at its initial point.
Syntax
The syntax of the REWIND
statement can take one of the following forms:
Long form:
REWIND (io-specifier-list) |
- integer-expression
is the unit connected to a sequential file or device.
- io-specifier-list
is a list of the following comma-separated I/O
specifiers:
- [UNIT=]unit
specifies the unit connected to an external file
opened for sequential access. unit must
be an integer expression that evaluates to a number greater than
0. If the optional keyword UNIT=
is omitted, unit must be the first item
in io-specifier-list.
- ERR=stmt-label
specifies the label of the executable statement
to which control passes if an error occurs during statement execution.
- IOSTAT=integer-variable
returns the I/O status after the statement
executes. If the statement executes successfully, integer-variable
is set to zero. If an error occurs, it is set to a positive integer
that indicates which error occurred.
Description
The REWIND
statement repositions the file connected to the specified unit at
the start of the first record. If the file is already at its starting
point or if the unit is not connected to a file, the REWIND
statement has no effect.
Examples
The following example of the REWIND
statement repositions the file connected to unit 10 to its initial
point:
The next example repositions to its initial point the file
connected to unit 21. If an error occurs during the execution of
the statement, control passes to the statement at label 99, and
the error code is returned in ios:
REWIND (21, ERR=99, IOSTAT=ios) |
Related statements
BACKSPACE,
ENDFILE, and
OPEN
Related concepts
For information about I/O concepts, see Chapter 8 “I/O and file handling”. This chapter
also lists example programs that use I/O.
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